veloroutes.org: This is my all-time favorite. It uses google maps, but in addition, you can draw your route and get the elevation chart instantly. For some countries, you can even use the the auto-routing Beta version, which allows you to simply give points A and B and get the elevation chart for the route between these two points. When this feature is not available (usually in non-Western countries), you have to draw the entire route point by point.

openrunner.com: This is a similar version of the above with a better design but without the auto-routing feature (in French, English, and Italian).

University of Texas has an online library with all sorts of maps for every region and country around the world.

For those of us who aren't high-tech or want to leave the netbook at home, I have found that State Gazatteer's published by DeLorme are very useful for bicycle touring, especially for routes that haven't been mapped by ACA or others. The scale of maps are perfect for finding the back roads (1:150,000) and they show commercial and state/federal campgrounds on the maps. I cut out the pages I plan to use while on tour. They are also great to use together with ACA maps in case you want to go off route for a couple of days. The commercial campgrounds are listed on a separate page at the front the Gazateer, so I also cut that page out too. The Gazatteer's are available at Amazon and run about $20 per state, so they aren't free.

Thx for the tip.I agree Gazatteers makes some good and affordable maps, one can even see the relief which I like when I use a map while bicycle touring. The only downside is that there is no decent overview of the whole state which make it hard to plan the trip.